Video demonstration from Full Droop TV on how to use dimple dies. (5 minutes 50 seconds in)

Dimple dies will work on plate up to 3/16 thick on a 20 ton hydraulic press. Dimpling sheet metal in any race vehicle gives it more strength and removes weight. These dimple dies are made from 8620 bearing steel so they will not wear out. Rockwell hardness of 80.